various methods for improving the engine performance have been discussed. Most significant upon them is to reduce the obstruction in the flow of fresh mixture and burnt products. In addition to this by improving the inlet and exhaust valve timing. Increase in compression ratio and swept volume may also improve the engine parformance

1. Engine Performance
Improvement
Prof. (Dr.) M P Poonia
Director
NITTTR, Chandigarh

2. Actual
P–V Diagram
PMEP

3. Indicated Power
(IP)
IP =
𝑷 𝒎
×𝑳×𝑨×𝑵
𝟏𝟐𝟎
IP = 𝑷 𝒎
×𝑽𝑺×𝑵
𝟏𝟐𝟎
Where,
IP = Indicated Power, W
Pm = Mean Effective
Pressure N/m2
L = Stroke Length, m
A = Piston Top Area,
m2
N = Engine RPM

4.  Reduce resistance during
intake and exhaust stages:
multiple valve configuration
 Cool the air before allowing
it to enter the cylinder
 Fuel Injection: do away with
the carburetor >>>
Improvement of
Performance

5.  Increase the
compression ratio
 Increase the engine
displacement: more power
 Compress more air into the
cylinder during intake: using
supercharger and
turbocharger
Improvement of
Performance

6.  Reduce resistance
during suction – Air Filter
Improvement of
Performance

7.  Reduce resistance
during suction
 – Carburetor
Improvement of
Performance
Air in
Throttle
Air + Fuel

8.  Reduce resistance during
suction – Intake Manifold
Improvement of
Performance

9.  Reduce resistance during
suction – Inlet Valve
Improvement of
Performance
Patm
Pint < Patm
Intake manifold

10.  Reduce resistance during
suction – Valve Lift
Improvement of
Performance

11.  Reduce resistance during
exhaust – Valve Lift
Improvement of
Performance

12.  Reduce resistance during
exhaust- Manifold
Improvement of
Performance

13.  Reduce resistance during
exhaust – System
Improvement of
Performance

14.  Proper Valve Timing – Longer
Opening and Closing Timing
Improvement of
Performance

15. Improvement of
Performance
 Cool the air before allowing it
to enter the cylinder
ρair=
𝒑
𝑹×𝑻

16. Improvement of
Performance
 Fuel Injection: do away
with the carburetor

17. Improvement of
Performance
 Increase the compression ratio

18. Improvement of
Performance
 Increase the engine
displacement: more power
IP = 𝑷 𝒎
×𝑽𝑺×𝑵
𝟏𝟐𝟎

19. Improvement of
Performance
 Compress more air into the
cylinder during intake: using
supercharger and turbocharger.

20. FAQ
Indicated Power of a
4 – stroke engine is =
a) pmLAN b) 2pmLAN
c) pmLAN/2 d) 4pmLAN
where pm = mean effective
pressure,
L = stroke
A = area of piston and
N = rpm of engine

21. FAQ
If the intake air temperature of
an I.C. engine increases,
its performance will
a) increase
b) decrease
c) remain same
d) none of the mentioned

22. FAQ
(a)
(b)
(c)
(d)

23. FAQ
(a)
(b)
(c)
(d)

24. FAQ
(a)
(b)
(c)
(d)

25. Thanks